can not be installed from github tarballs

[tacaswell]

The tarballs that are published via github (ex on this page https://github.com/pytries/datrie/releases/tag/0.8) are generated by running:

git archive 0.8.2 -o datrie-0.8.2.tar.gz --prefix=datrie-0.8.2/

for the given tag. This is because the libdatrie submodule is not also archived and the source for the underlying library is missing. A quick google suggest that this is not easy to fix short of just vendoring the full library.

In Matplotlib we have a download_or_cache function for pulling a few external dependencies that we want to vendor on install, maybe something like that would work here (maybe as a backup?).

I think this is a long standing issue.